Circuit breaker defined

If the circuit breaker is excluded from the pump equipment boundary and is defined as part of the controller that includes the circuit breaker, starting circuit, and protective trip circuits, then the circuit breaker has failed. 

Relays have inputs from several current transformers (CTs) and the zone of protection is bounded by these CTs. While the CTs provide the ability to detect a fault inside the zone, circuit breakers (CBs) provide the ability to isolate the fault by disconnecting all of the power equipment within the zone. Thus, a zone bonndai y is usually defined by a CT and a CB. When the CT is part of the CB it becomes a natural zone boundaiy. When the CT is not an integral part of the CB, special attention must be paid to the fault detection and fault interruption logic. The CT still defines the zone of protection, but communication channels must be used to implement the tripping function. Figure 1 shows the zones of protection in a typical system. 

Other objeas may be used to describe the function of a motor or drive, a medium voltage circuit breaker, or a heat exchanger a complete reactor may be described as a collection of objects. Emerging standards such as STEP (the Standard for the Exchange of Product Model Data, ISO 10303 [5]) are defining modeis for the interchange of electronic data desaibing all types of... 

Service equipment. The necessary equipment, usually consisting of a circuit breaker or switch and fuses, and their accessories, located near the point of entrance of supply conductors to a building or other structure, or an otherwise defined area, and intended to constitute the main control and means of cutoff of the supply. 

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